Place Value

Money already uses decimals. 4.35 dollars is 4 whole dollars and 35 cents, and a cent is one hundredth of a dollar. The dot is the decimal point: whole numbers sit to its left, and parts of a whole sit to its right.

Each place to the right of the point is worth ten times less than the one before it. The first is tenths, the second hundredths, the third thousandths. In 2.468, the 4 means 4 tenths, the 6 means 6 hundredths and the 8 means 8 thousandths. It is the same pattern as whole numbers, where every step left is worth ten times more, simply carried on past the ones.

You can also read the digits after the point together. 0.35 is 3 tenths and 5 hundredths, and since each tenth is worth 10 hundredths, that is 35 hundredths in all. That is why 0.35 is read as thirty-five hundredths: the last digit names the size of the pieces, and the digits together count them.